If you're on a mission to have a fully mobile office, this app might seem like the answer to your quest. It offers to help you read Microsoft Office documents from any smartphone or tablet, but sadly, Office Reader is a massive disappointment as it offers limited functionality and is ad-infested.
This app only works with Word, Excel, and PowerPoint, but instead of letting you read the documents in their native format, Office Reader has to convert them to PDFs to display them. If you have a bigger file, that leads to a very long conversion process. It also means you'll have multiple copies of the document, which can lead to problems. When you're actually viewing the final copy, the app doesn't allow you to zoom in for easier reading. Office Reader will also randomly engage ads that take over your entire screen in the middle of reading your document. Since the app is strictly a reader app, you can't do any edits to the files you have.
When there already are Android apps that can let you edit, save, and share Office docs, the least this one could do is make them easy to view. Ad-infested Office Reader instead makes you jump through bizarre hoops to see the documents you need. Android's built-in readers through Google Docs will be much easier for you to use. If you still want more, then look into full Android Office suites.